Loss of oil pressure

[fourthgear]

I finally got a chance to take the 65 out for a good spin, even if it was only for 20+ miles , (the rain has been bad lately and I have been working a lot ) I came back after running one exit to get home on I 95 , keeping a moderate speed and I pulled in the drive way and up into the garage and all was OK until I stopped to put her in neutral , then the lifters started to make all kinds of noise(Jims hydraulics ),shut engine off and checked oil , it was fine ,pulled oil filter out of tank to see if I would get return and restarted motor , no return , no pressure , shut her down .

I checked to see if I had a plugged oil feed line , nope , pulled the rear exhaust to pull oil cover ( stock cast pump ) and check to see if the scavenger gears were working , all was turning over with motor turning over .

The only thing that I thought was odd ( and it my not be ) is when turning motor over , there was blow by with some oil from around the scavenger gears when turning her over , don't remember if it should be like that .

I pulled the oil pump ,just to make sure all was Ok with the pump side and could not find any thing out of the ordinary , seemed the key & drive gear are solid . Blew air pressure in oil feed passage to see if any passages were clogged , but air went where it should have even to the out side oilers to the heads and tappet blocks.

Any Ideas , gentlemen ? I will pull the timing cover tomorrow.

[hogboy52]

The blow-by is just crankcase pressure as both pistons are coming down and the breather closed. I'd guess the pump driven gear in the timing case has come off or the key has sheared or fallen out.

[fourthgear]

Oil pump drive shaft and gear feel to be solid and turns with motor . When I remove timing cover later today I will see how they look .

[fourthgear]

Removed the timing cover and found nothing out of spec's , every thing turns and key is in oil pump drive gear/shaft. It is strange that I lost oil pressure/flow when motor went to idle , why not when I was going 65MPH or 15 mph coming up my street ?. I am happy it did not happen doing 65, but if there was some thing going bad or out of spec's why would it wait until there was no load on the motor .

I lost no oil , it was not pumping into the motor . You would think if I had a out of spec bushing or bearing , It would have filled the crank case /gear case and come out the breather , since it was not returning to the tank .

The feed line from the tank is clear and the breather , & vent . I am beginning to believe it is a pump problem and I think I will install a new fangle S&S pump . I can not see a thing on this ( I think its a repop ) pump that would make me think it would not work , but I guess it didn't .

[Guest]

did you take the drive gear off of the shaft and look at the woodruff key ? if it shears it will still turn with the engine, just not all the time.

[jlaley]

Any chance the pressure relief valve stuck open?

[Panacea]

Fourthgear, Is it too late to bypass the oil filter to check for an obstruction?

[Cotten]

Fourthgear!

Sorry, but I gotta ask:

You are not running an evil Andrews A-grind, are you?

....Cotten

[Guest]

Lifters LOOSE in the bore

[jlaley]

Cotten, I don't want to hijack this thread, but can you elaborate on the evil A cam? My '54 had one in it when I bought it and it's almost ready to start and you have me scared now. What's the scoop? Thanks, Jim

[Cotten]

Jim!

The simple un-deniable truth is that Andrews are bare-assed liars when they declare that the A-grind will work with OEM hydraulics.
(Other designs of hydraulics are a toss of the dice.)

Maybe occasionally an A will keep hot OEM hydraulics filled at idle, with a later high volume pump, if lucky. Or maybe it will blow your right motorcase!

Either way, don't look to Andrews for solace.

Tell them I said so. They have heard it many times before from many others than I, I assure you all!

....Cotten

[hogboy52]

I don't know that it's unusual to have low oil pressure at idle after a long ride and I can't say about hydraulics as I've never had any but the oil pump is a simple device that can hardly help but to pump oil.
I would say to re-assemble it all, checking again that the gears are tight, and then remove the oil pressure switch and spin the motor over. You should know quickly if it is pumping.

[jlaley]

Thanks Cotten. If I'm running solids will I be OK? What is a good cam to run now a days? I'm not going to be hot rodding this bike much. It has T&O torque monster wheels, and 8.5:1 compression. Otherwise she's stock. Thanks again, Jim

[fourthgear]

I have not had time to remove oil pump drive gear , but the timing chest is open , so I plan on pulling every thing to inspect.

I'm running a Crane 300H cam just for the Hyd. lifters.

If oil was bypassing any thing in the cam chest it would still retrurn oil , I would think. The fact that the lifters started to make a lot on noise tells me they were not getting oil and of course the motor seemed to be running funny ( colasped lifters )

Oil filter is in the oil tank and I pulled the cap to see there was not return oil . I did check my oil cooler and blew air pressure through it and all I got was an oil bath , it was clear .

This oil pump worked for weeks , I started the motor every day and warmed it up and took short rides in between rain showers/work and had oil pressure every time untill this .

I'm using a new type of hose ( oil lines )and is it possible I colasped the feed line to the pump ? It is surposed to be reinforced , maybe its not up for the task at hand . I'm kinda grasping at any thing here !

The check valve and pressure regulator seemed fine .

Bottom line is , I no longer trust this pump and I will have to replace it if I do not find some thing else .

Tanks for the returns , I will let you know what if any thing I find upon further disassembly.

[Cotten]

Jim!

Your solids do not need a proper profile to keep them filled at low RPMs, of course.
But please keep it in mind that the life of needle bearing tappet rollers is shortened with solids, no matter which cam you use.

....Cotten